Drafting roll weighting mechanism



July 14, 1970 TARBQX 3,520,029

DRAFTING ROLL WEIGHTING MECHANISM Filed Sept. 13, 1968 United States Patent 3,520,029 DRAFTIN G ROLL WEIGHTIN G MECHANISM Philip B. Tarbox, Clemson, S.C., assignor t0 Maremont Corporation, Chicago, Ill., a corporation of Illinois Filed Sept. 13, 1968, Ser. No. 759,734 Int. Cl. D01h /46 US. Cl. 19-267 4 Claims ABSTRACT OF THE DISCLOSURE A weighting mechanism for the top front roll of a drafting assembly, the mechanism by leverage generating a roll weighting force of many times greater magnitude than the magnitude of the weighting spring employed therein. The mechanism includes an arm pivotably mounted adacent its rear end for movement between a raised inoperative position and a lowered operative position. The arm is releasably retained in inoperative position by a latch at its rear end, and in operative position by a toggle mechanism at its forward end. The arm preferably carries the front top roll of the assembly, and permits positional adjustment thereof relative to the front bottom roll.

This invention relates to textile fiber drafting assemblies, such as are employed in spinning frames and the like, and more specifically to an improved weighting mechanism for particularly the front top roll of such assemblies.

A mechanism according to the present invention achieves necessary roll weighting in a highly efficient manner, making maximum utilization of relatively inexpensive components which are compact in size and arrangement, while not impeding convenient positional adjustent of or access to the drafting rolls, so as to at all times permit optimum alignment therebetween. In its preferred form the mechanism so amplifies the force of a relatively small spring component as to generate therefrom a roll weighting force of some nine to ten times greater magnitude. The preferred mechanism is of simple yet durable construction and can, following disengage ment of a toggle conveniently located at its forward end be readily pivoted from an operative position wherein it closely overlies the drafting assembly, to a raised inoperative position wherein it is automatically retained so to fully expose the drafting rolls for purposes of inspection, maintenance or the like.

The foregoing and other features of the invention will be apparent from the following description of an illustrative embodiment thereof, which should be read in conjunction with the accompanying drawing, in which:

FIG. 1 is a front perspective view of a mechanism according to the invention in its operative position relative to a drafting assembly;

FIG. 2 is an enlarged and partially broken away vertical section taken approximately along the line 22 through the mechanism and the associated front top roll of FIG. 1, the toggle levers at the mechanisms front end being shown disengaged, and

FIG. 3 is a fragmentary horizontal section taken generally along the line 33 of FIG. 2 through the rear end of the mechanism.

Referring more particularly to the drawings, in FIG. 1 the numeral designates the frame of a textile machine, such as the beam of a worsted spinning frame, above and longitudinally of which extends a conventional drafting assembly consisting of serially arranged pairs of front, intermediate and rear drafting rolls, the roll series sloping upwardly from front to rear. Bottom rolls 12, 14, 16 may be conventionally supported upon beam 10 by suitable roll stands and bearing blocks (not shown) and customarily extend the full length of the beam to a drive mechanism at one end thereof. The shorter top rolls of the assembly, which are of standard double-bossed construction and the intermediate one of which may be provided with aprons 18, rest upon and are driven by their associated bottom rolls, the intermediate and rear top rolls 14, 16' being supported thereon by suitable cap bars (not shown) or the like. The larger diameter front top roll 12' of the drafting assembly is supported upon and urged firmly against its associated bottom roll 12 by a mechanism 20 which, in accordance with the present invention and as shown in FIG. 1, includes an elongate arm 22 extending forwardly from a rod 23 carried by the roll stands or any other convenient part of the machines frame in rearwardly and upwardly spaced parallel relation to bottom rear roll 16. The opposite end of arm 22 is disposed forwardly of front rolls 12, 12' above the front edge of :beam 10.

Referring now also to FIGS. 2 and 3, arm 22 preferably has two mating and telescopically adjustable sections, a forward section 22' and a rear section 22", and mechanism 20 further comprises toggle means including pivotally connected links 26, 28, roll engaging means including saddle 30 and spring 32, support means including bracket 34 and stud 36, biasing means including spring 38, and latch means including latch plate 40 and collar 42. Bracket 34 is generally of inverted-U shape, its downwardly extending leg portions 34 having bores aligned with that of the collar 42 positioned therebetween for passage therethrough of rod 23. Collar 42 is rigidly secured in a desired adjustive position upon rod 23, as by means of set screw 43, and is provided with spaced notches 42, 42" in its cylindrical surface. Once collar 42 is secured in place, engagement between its ends and the adjacent legs 34 of bracket 34 prohibits movement of the bracket longitudinally of rod 23. Engagement between collar notch 42' and a stop pin 44 spanning bracket legs 34' prohibits fur ther clockwise pivotal movement of bracket 34 from its illustrated position, while permitting counter-clockwise movement thereof when desired through an arc of approximately 40. Upright stud 36 extends generally radially of rod 23 through the approximate center of bracket 34, its threaded upper end projecting through a bore there provided and :being secured to the bracket by a nut 46, and its enlarged lower end being positioned between bracket legs 34 above collar 42. Coil spring 38, which is of the compression type, encircles the middle portion of stud 36 and at its upper end engages the adjacent surface of bracket 34.

As is best shown in FIG. 2, rear section 22 of arm 22 projects between bracket leg portions 34 and is pro vided with a bore through which stud 36 extends, the arm section being disposed thereon above the studs enlarged lower end and below spring 38. The connection therebetween is such that stud 36 mounts arm 22 for pivotal movement with bracket 34 in a generally vertical plane about the axis of rod 23, and also for limited pivotal movement relative to the bracket about the stud axis in a plane approximately perpendicular to the aforesaid vertical one. In order not to impede the latter pivotal movement, a slight clearance is provided between bracket legs 34' and the adjacent sides of generally bar-shaped arm section 22 (see FIG. 3). The connection between stud 36 and rear section 22" of arm 22 also permits movement of the latter longitudinally of stud 36, and spring 38 tends to produce such movement in a downward direction.

The free end of arm section 22" at the rear of bracket 34 has a transverse pivot pin 48 brazed or otherwise suitably secured thereto and projecting beyond its side edges. The projecting pin ends pivotally mount latch plate 40, which extends upwardly and also angularly downwardly therefrom. A forwardly projecting foot 40' at the lower end of latch plate 40 rests upon the cylindrical surface of collar 42. Upon pivotal movement of arm 22 in an upward clockwise direction to an inoperative position, wherein it extends generally horizontally in spaced relation to the drafting assembly, latch foot 40' is received within collar notch 42" so as to releasably latch the arm in place. The upper end of latch plate projects slightly above bracket 34 so that it may be readily pivoted forwardly when desired, thus releasing the latch mechanism and allowing return downward movement of arm 22 to its illustrated operative position.

In front of bracket 34, arm section 22" extends first upwardly and then forwardly a short distance. The forward projection of arm section 22" is matingly received between the downwardly extending side flanges of the considerably longer arm section 22', which is generally of inverted channel shape. A bolt 50, carried by a threaded bore of arm section 22" and projecting upwardly through an elongate slot 52 provided within arm section 22, serves when tightened to secure the arm sections together, being assisted in this regard by the preferably close mating relationship of the sections. The effective length of arm 22 may be varied, as desired and within the limits imposed by the opposite ends of slot 52, by loosening bolt 50 and sliding arm section 22 longtiudinally of arm section 22".

The aforesaid capability for adjustment of arm 22s effective length permits top roll 12' to be precisely located upon and slightly forwardly of its associated bottom roll 12, since roll-engaging saddle 30 is carried by adjustablymovable arm section 22' adjacent its forward end. Saddle 30 preferably comprises downward projections of the side flanges of arm section 22', the lower edges thereof being appropriately notched so as to partially encircle the center shaft of roll 12'. The roll shaft is supported from below by spring clip 32, one end of which is riveted I at 33 to arm section 22, such that roll 12' may be releasably retained by arm 22 during its movement to and from its inoperative position.

A second projection of the side flanges of arm section 22' defines a pair of spaced parallel ears 54 extending forwardly from the free end thereof. Pins 56 pivotally interconnect ears 54 to the shorter leg of the generally L-shaped toggle link 26 disposed therebetween, which link is in turn pivotally and somewhat loosely connected by a pin 58 to the second toggle link 28. Link 28 has at its lower end a slotted foot 60 which, in the engaged FIG. 1 condition of the toggle mechanism, straddles an anchor bolt 62 upon beam 10. Disengagement of the toggle mechanism and of foot 60 from anchor 62 may be easily efiected when desired simply by pivoting toggle link 26 in a counter-clockwise direction from its FIG. 1 position wherein it rests upon arm section 22, to an open position such as illustrated in FIG. 2, the free end of link 26 being provided as shown with transversely extending tabs to facilitate its being grasped and so moved.

When mechanism 20 is idle, arm 22 may as previously noted be pivoted upwardly to an inoperative position wherein it extends generally horizontally from rod 23. Ann 22 is automatically latched and retained in such position, which affords ready access to all of the rolls of the drafting assembly, by plate 40 and the other components of the latch mechanism at its rear end. Upon release of the latch mechanism, the arm descends until the roll 12 which it carries rests upon roll 12, a properly offset relationship between the rolls being assured by the capability for adjustment of the arms effective length. Further pivotal movement of arm 22 about the axis of rod 23, to any appreciable extent in a counter-clockwise direction, is then prohibited by engagement between stop pin 44 and collar notch 42'. The toggle mechanism at the arms forward end is, next, anchored to beam and engaged by pivoting link 26 rearwardly. Engagement of the toggle mechanism, while so locking arm 22 in its operative position as to negate its prior capability for pivotal movement about rod 23s axis, establishes another pivotal axis-coincident with that of toggle pin 58-extending generally parallel thereto at the opposite arm end. In the closed condition of the toggle mechanism, pin 58 is disposed above pin 56 closely adjacent both the extreme forward end of arm 22 and the roll-engaging saddle 30 carried thereby. By a leverage effect, therefore, the weighting force exerted downwardly upon roll 12 through saddle 30 is many times greater than the force of the spring 38 producing such roll weighting. More specifically, the roll weighting force will be approximately equal to the force of spring 38 times the ratio of the distances X, Y longitudinally of arm 22, the distance X between the active position of pin 58 (shown in phantom lines in FIG. 2) and the rear arm end engaged by spring 38 preferably being at least approximately nine to ten times the distance Y between pin 58 and the effective center of saddle 30. Realization of a roll weighting force of, say, approximately 130 lbs. with a mechanism wherein the X, Y distances are roughly 13.75 inches and 1.50 inches, respectively, thus requires only a relatively small and inexpensive spring 38 capable of exerting approximately a 14.25 lb. force. After roll weighting has been achieved in the aforesaid manner and the drafting assembly commences its operation, roll 12' will if inadvertently slightly canted automatically correct such misalignment of its axis relative to that of roll 12. The connections of the respective opposite ends of arm 22 to bracket 34 and beam 10 are such as to afford suflicient lost motion in a lateral direction for the corrective movement of the roll and arm to occur, thus further insuring optimum operation of the drafting rolls.

While a specific embodiment of the invention has been shown and described, this was for purposes of illustration only, since modifications and other embodiments thereof will be apparent to those skilled in the art and are within the scope of the following claims.

That which is claimed is:

1. A top roll weighting mechanism for a textile drafting assembly having front and rear pairs of superposed top and bottom rolls, said weighting mechanism comprising:

an elongate arm extending forwardly and rearwardly above said drafting assembly; means mounting said arm for pivotal movement about a generally horizontal axis adjacent the rear end thereof between an operative lowered position wherein said arm closely overlies said drafting assembly and an inoperative raised position; a saddle adjacent the forward end of said arm adapted to engage the front top roll of said assembly;

means releasably locking said arm in its operative position and then mounting said arm for limited pivotal movement about a second generally horizontal axis adjacent and forwardly of said saddle;

means biasing the rear end portion of said arm pivotally downwardly about said second axis to weight the top front roll of said assembly, through said arm and said saddle, against the bottom front roll;

and length adjusting means intermediate said saddle and said biasing means for adjusting the effective length of said arm.

2. A mechanism as in claim 1, wherein said means mounting said arm for pivotable movement between operative and inoperative positions includes a rod extending generally parallel to and rearwardly of the rear rolls of said assembly, a bracket mounted upon and pivotable 5 said arm being movable to a limited extent about and generally longitudinally of the axis of said stud. 3. A mechanism as in claim 1 wherein said biasing means comprises a coil spring encircling said stud and acting against the there adjacent portion of said arm.

4. A mechanism as in claim 3, wherein said means releasably locking said arm in its operative position includes pivotally interconnected toggle links carried by said arm, and said second axis is that of the pivotal intel-connection of said links.

3,412,434 11/1968 Fusaroli 19267 DORSEY NEWTON, Primary Examiner US. Cl. X.R. 

